matrices

[Clifford]

Is my multiplying right?

Don't mind the all the funky signs, the last numbers are the numbers of that actual position.

\(\displaystyle \[
\begin{array}{l}
\left[ {\begin{array}{*{20}c}
{18} & 3 \\
{ - 83} & { - 12} \\
\end{array}} \right]\; \times \;\left( {\left[ {\begin{array}{*{20}c}
1 & { - 3} \\
{ - 2} & {27} \\
\end{array}} \right]\; \times \;\left[ {\begin{array}{*{20}c}
{15} & { - 7} \\
{ - 7} & { - 3} \\
\end{array}} \right]} \right) \\
\left[ {\begin{array}{*{20}c}
{18} & 3 \\
{ - 83} & { - 12} \\
\end{array}} \right]\; \times \;\left[ {\begin{array}{*{20}c}
{36} & 2 \\
{ - 219} & { - 67} \\
\end{array}} \right] \\
\left[ {\begin{array}{*{20}c}
{ - 9} & { - 165} \\
{ - 360} & {780} \\
\end{array}} \right] \\
\end{array}
\]\)

 

[mark07]

\(\displaystyle \[
\begin{array}{l}
\left[ {\begin{array}{cc}
{18} & 3 \\
{ - 83} & { - 12} \\
\end{array}} \right]\; \times \;\left( {\left[ {\begin{array}{cc}
1 & { - 3} \\
{ - 2} & {27} \\
\end{array}} \right]\; \times \;\left[ {\begin{array}{cc}
{15} & { - 7} \\
{ - 7} & { - 3} \\
\end{array}} \right]} \right) \\
\left[ {\begin{array}{cc}
{18} & 3 \\
{ - 83} & { - 12} \\
\end{array}} \right]\; \times \;\left[ {\begin{array}{cc}
{36} & 2 \\
{ - 219} & { - 67} \\
\end{array}} \right] \\
\left[ {\begin{array}{cc}
{ - 9} & { - 165} \\
{ - 360} & {638} \\
\end{array}} \right] \\
\end{array}
\]\)

(2,2)-entry is 638, not 780.